A Simple One-Pot Method for the Synthesis of BiFeO/BiFeO Heterojunction for High-Performance Photocatalytic Degradation Applications.

This study presents a facile one-pot synthesis method to fabricate BiFeO-BiFeO-BiO heterojunction photocatalysts with controllable compositions and pure phases. Three different binary heterojunctions (BiFeO/BiFeO, BiFeO/BiO, and BiFeO/BiO) and a ternary BiFeO/BiFeO/BiO heterojunction were formed, all exhibiting significantly enhanced photocatalytic performance for the degradation of methylene blue (MB) and phenol under visible light irradiation, outperforming the individual compositions. Notably, the BiFeO/BiFeO heterojunction achieved the highest degradation efficiency (93.68% and 83.3% for MB and phenol, respectively) as well as excellent stability. Impressively, the phenol degradation efficiency of BiFeO/BiFeO was even over twice that of BiFeO and BiFeO, and four times higher than that of BiO. The enhanced photocatalytic activity of the BiFeO/BiFeO heterojunction is primarily attributed to the advantageous S-scheme band alignments that facilitate efficient charge separation and enhance redox capabilities. While other heterojunctions also exhibited improved MB and phenol degradation efficiency, each unique combination of materials led to distinct electronic structures and diverse reaction mechanisms. The simplicity and scalability of the synthesis method, combined with the remarkable photocatalytic performance of these BiFeO-BiFeO-BiO heterojunction materials, position them as highly promising candidates for applications in environmental remediation and solar energy conversion.